Make distcheck use the tarball submodule directories

When Distcheck runs, it invokes `make check` with the current
directory set to `<git_root>/build/tmp/distcheck` which contains an
extracted plain source tarball.

Without passing `--src`, bootstrap's `compute_src_directory` will call
`git rev-parse --show-cdup` from that tmp directory and get back to
`<git_root>`

At that point all the `git_info` calls will find submodules in the
original git checkout, not in the tarball.

If we instead pass `--src`, `compute_src_directory` will use the
argument directory and all the git info commands will use the tarball
git-commit-info files.

Additionally, we update tidy's `gcc_submodule` check to look for the
`src/gcc/notice.txt` file that is present in tarballs to indicate that
we did not include the `src/gcc` submodule.

Author: lambdageek

src/bootstrap/mk/Makefile.in

@@ -13,7 +13,7 @@ ifdef MAKEFLAGS
   endif
 endif
 
-BOOTSTRAP := $(CFG_PYTHON) $(CFG_SRC_DIR)src/bootstrap/bootstrap.py
+BOOTSTRAP := $(CFG_PYTHON) $(CFG_SRC_DIR)src/bootstrap/bootstrap.py --src $(CFG_SRC_DIR)
 
 all:
 	$(Q)$(BOOTSTRAP) build --stage 2 $(BOOTSTRAP_ARGS)
@@ -46,7 +46,7 @@ book:
 standalone-docs:
 	$(Q)$(BOOTSTRAP) doc --stage 2 src/doc $(BOOTSTRAP_ARGS)
 check:
-	$(Q)$(BOOTSTRAP) test --stage 2 $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) test --verbose --stage 2 $(BOOTSTRAP_ARGS)
 check-aux:
 	$(Q)$(BOOTSTRAP) test --stage 2 \
 		src/tools/cargo \

src/tools/tidy/src/gcc_submodule.rs

@@ -13,6 +13,11 @@ pub fn check(root_path: &Path, compiler_path: &Path, bad: &mut bool) {
         .trim()
         .to_string();
 
+    // If we're in a tarball, there is no gcc submodule
+    if root_path.join("src").join("gcc").join("notice.txt").exists() {
+        return;
+    }
+
     let git_output = Command::new("git")
         .current_dir(root_path)
         .arg("submodule")